Sigma 24/2.8 XQ Filtermatic

[Farside]

Just got this today.




That silver button on the lens base, next to the Raw button is a stopdown button, just like the OM lenses. Very very useful and situated perfectly for K10D use.






Annoyingly, there's something wrong with the optics on the top left corner - a bit of image ghosting. Oddly, it didn't show up in pics taken around the corner, only on the ones at the crossroad. Perhaps the building is drunk.




You can see the onset of the veiling flare to the top left - this lens definitely needs a hood.

I will keep this for a while and see what other quirks it has. It's sharp enough for web use and small enlargements, but the corners let it down a bit - possibly been dropped or messed about with in the past thirty years, who knows.
I find the built-in filters intriguing - if for no other reason than that, I will keep this at least for B&W photography. I've just noticed something else - the filters are part of the optical system, and not optically neutral, ie, they definitely affect focus, things snapping in and out of focus as the filters move in and out of position.
There's an L 1A, Y48, O56, and LB82C on the ring around the front.

[casualcollector]

Very interesting! Perhaps your filters aren't quite properly positioned and that may explain the double image. Have some fun with it!

[Farside]

It certainly deserves investigation, I'd like to have it working properly. Something rattles in it, perhaps related. Oddly, the grey cottages have turned out blue, and that was after correcting them a bit, earlier on. The coloured filters are quite distinct and the 1A seems clear enough, so perhaps it tends to produce a cold image, natively. It's almost as if I had a mild blue filter in place, but I know I didn't.